Multisite Left Ventricular Pacing Improves Acute Mechanical Dyssynchrony in Heart Failure Patients

Methods: Patients (N=33) undergoing or recently receiving a CRT implant were studied at 7 sites. Each patient underwent an acute pacing protocol comprising BiV simultaneous pacing (BASELINE) and a set of 8 MPP interventions covering a range of LVLV and LVRV delay combinations. Pacing rate was ixed during the protocol. Transthoracic tissue Doppler imaging was performed at all pacing interventions. Raw data were analyzed by the core lab and mechanical dyssynchrony was measured as the standard deviation of time to peak contraction of 12 segments (Ts-SD). A threshold of 20% reduction in Ts-SD compared to BASELINE was used to deine signiicant improvement in dyssynchrony.